The present invention relates to a vane compressor, and more particularly to a vane compressor for use as a refrigerant compressor in an automobile air conditioning system.
Vane compressors have a working chamber defined by the outer periphery of a rotor, side surfaces of vanes, the inner surface of a housing, and the inner surfaces of side plates. As the rotor rotates, the working chamber varies its volume to draw and discharge a refrigerant. Studies conducted by the inventor of conventional vane compressors have indicated that the rotor and the housing are subjected to much scuffing at one end surface of the rotor in operation.
Such scuffing appears to be caused, according to the inventor, for the following reason:
Any pool of liquid refrigerant left in the working chamber is compressed especially when the compressor is started. When this happens, as shown in FIG. 1 of the accompanying drawings, an unduly high pressure is exerted on vanes 1 which cause vane slots 2 to be widened. Since the vane slots 2 are cut out in the rotor 3 from one end surface 3a thereof, the vane slots 2 are widened to a larger extent particularly at such rotor end surface 3a. Therefore, the rotor 3 is radially outwardly enlarged especially at the end surface 3a into pressing engagement with an inner surface 8a of the housing 8, with the result that the rotor 3 and the housing 8 are scuffed.